Diogenes planimanus Henderson, 1893

Rahayu, Dwi Listyo, 2022, Hermit crabs of Singapore (Crustacea: Decapoda: Anomura: Diogenidae, Paguridae), with description of two new species, Raffles Bulletin of Zoology 70, pp. 329-363 : 335

Diogenes planimanus Henderson, 1893

( Figs. 3C, D , 4B )

Diogenes planimanus Henderson, 1893: 416 , pl. 39, figs. 5, 6 (type locality: Madras, India); Tirmizi & Siddiqui, 1982: 43, figs. 21, 22; Rahayu, 1996: 345, fig. 3; McLaughlin & Clark, 1997: 40, figs. 4a, 9c, e, 12a; McLaughlin, 2002a: 422, fig. 5A–C; Siddiqui, Kazmi & McLaughlin, 2004: 164, figs. 3, 4.

Material examined. 3 males, 4.0– 6.7 mm, 1 female, 6.7 mm ( ZRC 2021.0112 ), Red Cliff shoal area, Changi, 27 April 1982 ; 1 male, 8.44 mm ( ZRC 2021.0113 ), Kranji Reservoir park, 1°26.27.9′N 103°44.16.26′E, 4 July 2009 .

Distribution. Northern Arabian Sea, Bay of Bengal, Andaman Sea, Singapore, Malaysia, Gulf of Thailand, and northern Australia; intertidal to 7 m, inhabits sandy mud substrate.

Remarks. In having a shield that is denticulate over the entire length of its anterior margin, a weakly bifurcated antennal acicle, tuberculation of the chelipeds, the covering of tubercles on the lateral faces of the propodi, carpi, and meri, and the rows of spines on the dorsal surface of propodi and carpi of P2 and P3 ( Fig. 3D ), the present specimens agree well with the lectotype of D. planimanus redescribed by McLaughlin & Clark (1997) and specimens from Pakistan examined by Siddiqui et al. (2004). They differ from the lectotype in having only one spine on each side of the intercalary rostriform process (two or five spines on each side in the lectotype). Rahayu (1996), McLaughlin & Clark (1997), and Siddiqui et al. (2004) mentioned the presence of blunt or acute tubercles on the surface of the palm and fixed finger of the left cheliped. The tubercles on the outer surface of the palm and fixed finger of the left cheliped in the present specimens are more flattened, none of which are acute ( Fig. 3C ), however a prominent row of tubercles on the outer surface of the carpus of the left cheliped is clearly indicated ( Fig. 3C ).

Figures

Fig. 3. A, B, Diogenes mixtus Lanchester, 1902, male, 8.0 mm (ZRC 2021.0111); C, D, Diogenes planimanus Henderson, 1893, male, 6.7 mm (ZRC 2021.0112). A, C, left cheliped, dorsal view; B, D, left P2 and P3, lateral view.

Fig. 4. A, Diogenes mixtus Lanchester, 1902, male, 8.0 mm (ZRC 2021.0111); B, Diogenes planimanus Henderson, 1893, male, 6.7 mm (ZRC 2021.0112).